Garbage toxins suspected of contaminating hawks

Researchers have found high levels of toxic flame retardants in Lower Mainland raptors, including one Cooper’s hawk in Langley with the highest levels of the contaminant ever recorded in a wild bird.

The average concentration of PBDEs, a flame retardant used on furniture, electronics and carpets, averaged 1,873 parts per billion in the livers of 15 raptors tested in the Lower Mainland, and that reading hit 197,000 in the case of the Langley hawk.

The birds tested between 2000 and 2009 had all died from being hit by cars or similar trauma.

Lead researcher Kyle Elliott, from McGill University, says more species are adapting to urban areas, where they encounter higher levels of chemical pollutants, which can then bioaccumulate in top predators. Hawks, for example, eat starlings that often feed on garbage.

Elliott said it’s impossible to say the ultra-toxic hawk was contaminated by the waste transfer station in Langley – a scenario Metro Vancouver officials doubt because garbage there is swiftly compacted, giving birds little access – but he suspects avian access to garbage is part of the overall problem, whether it’s via landfills, dumpsters or bagged garbage at the curb.

“There were very high levels across the entire Lower Mainland,” he told Black Press.

“We do know these brominated flame retardants are often associated with human refuse. And starlings have 15 times higher levels near the Burns Bog landfill as compared to other sites in the Lower Mainland.”

Elliott said the PBDE levels found in Cooper’s hawks in the Lower Mainland were higher than found in any other study elsewhere.

The Langley hawk, found dead in 2002, showed no signs of emaciation or sickness but had PBDE levels 100 times higher than levels known to decrease thyroid levels in eagles and suppress the immune system in kestrels, Elliott said.

The findings were published in a research paper in the journal Science of the Total Environment.

More research is underway to gauge the sources and effects of chemicals like PBDEs on a breeding group of Cooper’s hawks in the Metro Vancouver area.

The Orphaned Wildlife Rehabilitation Society (OWL) in Delta often takes in injured raptors found near the Vancouver landfill in Delta with injuries or infections that defy explanation and make treatment challenging, according to bird care supervisor Martina Versteeg.

“We definitely think it has something to do with human waste,” she said.

“We see birds come in with infections, inflammation, pus – all these things – and the test results often come back sterile. So what is it? Is it the chemicals or flame retardants doing it?”

Versteeg says OWL urges supporters to recycle as much as possible to limit bird and wildlife access to garbage.

“One time we had an eagle that coughed up the handle of a women’s razor,” Versteeg said. “It was pink so it looked like a piece of fish. And if they’re fighting over it they may just swallow it real quick and go on their day. She came here and coughed that up.”

Use of PBDEs was restricted several years ago but old products continue to end up in landfills so the legacy chemicals can have a lingering effect in the environment.